Ship s binnacle



(No Model.)

J. L. BLISS. SHIPS BINNAGLE.

No. 448,201. Patented Mar. 17,1891.

. vuorovm Unire @rares Partnr Ormes.

.IOHhY L. BLISS, OF BROOKLYN, NENV YORK.

si-:uws BINNACLE.

SPECIFISATION forming part of Letters Patent No. 448,201, dated March 17, 1891.

Application tiled December 13, 1890. Serial No. 374,572. (No model.)

T0 all whom 'it may concern.-

Be it known that I, JOHN L. BLISS, of the city of Brooklyn, in the countyof Kings and State of New York, have invented a new and useful Improvement in Ships Binnacles, of whichthe following is a specification, reference being had to the accompanying drawings, forming a part thereof,

My invention relates to means provided in ships binnacles for the reception of magnets for the purpose of correcting the semicircular error in the compass. The magnetic force exerted by an iron ship caused by the horizontal component of the sub-permanent magnetism of the ship and by the magnetism induced in vertical iron by the vertical component of the earths force is for purposes of compensation usually considered to be resolved into two components, one acting in a direction parallel to the ships keel or fore and aft, the other in a direction at right angles to the ships keel or thwart ship. To effect a compensation for these disturbing forces, it is customary to introduce compensatin g magnets placed in the foi e-and-aft and thwart-ship directions adjacent to the compass, according to the method proposed by the late Professor Airy, Astronomer Royal of Great Britain.

The object of my invention is to provide a more convenient and accurate means of applying such magnets than heretofore.

I will now proceed to describe my invention with reference to the accompanying dravings, and then point out the novel features in claims.

Figure 1 is a view in side elevation of a ships binnacle embodying my invention, a compass being shown therein in dotted outline. Fig. 2 is a view in cross-section of Fig. 1, the section being taken on the line man Fig. 3 is a detail view of one of the compensating magnets I employ.

Similar letters of reference designate corresponding parts in all the gures.

In the drawings, A represents the frame of the binnacle, and B the compass in dotted outline.

C designates a shallow cupboard, which contains a vertical series of horizontal shelves c. The space between any two of said shelves is designed to receive a magnet, and in order to facilitate the insertion and removal thereof I have provided each shelf with a recess c', formed by cutting away a portion of the shelf, which will permit of the finger and thumb being placed on either side of the magnet in order to remove the same.

In Fig. l I have shown three magnets in position'for correcting the fore-and-aft componen t, the dark-shaded portions d representing the true north poles and the light-shaded portions Cl the true south poles. The object of having the shelves arranged in a Vertical series is that the greater the distance between the magnet and the compass the less the correcting force of the magnet. IIence, 4supposing two magnets in the two lowest shelves over-compensate the error, I can reverse the lower one and raise the upper until the desired amount of compensation is obtained.

I have shown two cupboards O in the thwartship direction, one on each side of the binnacle, as in this direction whatever magnets are used on one side must be duplicated on the other, in order that when the ship is rolling and the compass is raised on one side and lowered on the other the increase of correcting force on the side at which the compass lowers is counterbalanced by the decrease on the opposite side thereof. I lconsider one sufficient in the fore-and-aft direction, as the amount of pitching is not as a rule sufficient to seriously affect the compensation in that direction.

In the drawings I have represented the arrows w as pointing in the fore-and-aft direction, and the arrows o as pointing in the thwart-ship direction.

I have shown doors E as hinged at c and adapted when closed to hold the magnets securely inposition, as it is very important that they should not shift in the slightest degree, a very small movement, especially in the npper shelves, seriously affecting the compensation.

One advantage I wish to claim for my system of shelves is that while adjusting' the magnets and removing them from one shelf to the other the said magnets are always kept in the same relative position laterally with the center of the compass. Supposing them to be drawn out sidewise, for instance, the effect on the compass while a change is be- IOO ing' made would he to pull the compass round ont of position :L very great deal more than necessary, and so much time would be Wasted While the compass was coming back again before @correct reading could be taken.

Vhat I eieiin as my invention, and desire to secure by Letters Patent, is'- l. The combination, in L hinnaoie, of e eupboard on eithell side thereof provided with a, vertical series of shelves, and a door forming a closure for said cupboard and for the several spaces between said shelves, substantially es and for the purpose herein set forth.

2. The combination, in e hinnneie, of n euphonrd on either side thereof provided with a vertical series of horizontal shelves having; recesses, and a door forming a closure for seid cupboard and for the several spaces between said shelves, substantially as and for the purpose herein set forth.

JOHNu L. BLIss.

Witnesses:

FREDK. HAYNEs, C. E. SUNDGREN. 

